Browser+LibWeb+WebContent: Allow Browser to load local files

To achieve this goal:
 - The Browser unveils "/tmp/portal/filesystemaccess"
 - Pass the page through LoadRequest => ResourceLoader
 - ResourceLoader requests a file to the FileSystemAccessServer via IPC
 - OutOfProcessWebView handles it and sends a file descriptor back to
 the Page.

Userland/Libraries/LibWeb/Loader/FileRequest.cpp

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2022, Lucas Chollet <lucas.chollet@free.fr>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "FileRequest.h"
+
+namespace Web {
+
+FileRequest::FileRequest(String path)
+    : m_path(move(path))
+{
+}
+
+String FileRequest::path() const
+{
+    return m_path;
+}
+
+}